Multiple Ultrasound Inputs

Hi, I have a circuit designed to read an ultrasound pulse and amplify it with an op amp and comparator so an mcu can detect the pulse.

My question is: What if i want to have say 2 or more transducers input to the amplifier. Do i need a separate amplifier for each transducer or can i somehow combine them.

I can't seem to find any spice models for how US transducers behave.

They are just like microphones, so if you want to combine them then treate them as two sources with a mixer circuit. However I would use a buffer amplifier or voltage follower on each transducer to stop cross talk.